Let us say that the scandal du jour is no longer about Stephanie Grace, the Harvard 3L in question: she has apologized categorically [scroll down], and without any offensive hedges, for the ignorant e-mail. The real interest of this matter now lies in what it reveals about the right-wing mindset and its capacity to rationalize, well, just about anything. (Talk about "epistemic closure"!)

There is an important position in epistemology that travels under the heading of "fallibilism," which is common to all radical empiricists from Mill to Quine, according to which we have to allow the possibility that anything we presently take ourselves to be justified in believing may turn out to be false (or, more precisely, may turn out not to satifsy present or future standards of evidence). There is no epistemic certainty to be had with regard to anything. So, e.g., a fallibilist can happily admit that, "It is possible we may have to abandon modus ponens" and "It is possible that we will have to give up the theory of gravity." No fallibilist would follow this, however, with a statement like, "Of course, I'm ready to hang on to modus ponens if we could just find more evidence for it," or, "I am willing to accept the theory of gravity if we can just explain how that squares with the expansion of the universe." That's not an expression of fallibilism, because it implies not that a contrary position is possible, but that there is some evidence for the contrary proposition, which now mandates countervailing evidence for belief still to be warranted. (This recent review essay actually has lots of interesting, albeit mildly technical, philosophical discussion of the whole topic which is not irrelevant to the current discussion.)

A lot of the blogospheric blather about the racist e-mail makes Ms. Grace out to be an honorable fallibilist by laying all the emphasis on just one sentence from her e-mail: "I absolutely do not rule out the possibility that African Americans are, on average, genetically predisposed to be less intelligent." Considered in isolation, that sounds like sensible fallibilism, compatible with believing that there is no evidence for this proposition, but it is a possibility that any fallibilist must acknowledge. But read in context, her statement was quite obviously nothing of the kind. So let's add some of the context:

I absolutely do not rule out the possibility that African Americans are, on average, genetically predisposed to be less intelligent. I could also obviously be convinced that by controlling for the right variables, we would see that they are, in fact, as intelligent as white people under the same circumstances. The fact is, some things are genetic. African Americans tend to have darker skin. Irish people are more likely to have red hair. (Now on to the more controversial:) Women tend to perform less well in math due at least in part to prenatal levels of testosterone, which also account for variations in mathematics performance within genders. This suggests to me that some part of intelligence is genetic, just like identical twins raised apart tend to have very similar IQs and just like I think my babies will be geniuses and beautiful individuals whether I raise them or give them to an orphanage in Nigeria.

Here is the natural interpretation of this paragraph: she is not ruling out the possibility that African-Americans are "genetically predisposed to be less intlligent" because she thinks there is some evidence for that proposition, evidence which would have to be defeated or explained away. That is why the third of my three "uncontroversial" propositions was:

3. There is no evidence--literally, none--that IQ differences between racial groups have a genetic basis.

And that is why I criticized her for her "ignorance...skewed in favor of racist stereotypes." In the absence of any actual evidence supporting her suspicions about the genetic inferiority of African-Americans, she was clearly prepared to assume there was such evidence--which, of course, is just what a racist would do.

In response to the earlier post, various e-mailers and bloggers proceeded to cite the heritability studies (apparently not noticing my first "uncontroversial" proposition, namely, that "There is substantial evidence that IQ is heritable"), without bothering, it appears, to read the essay by Ned Block I referenced, which makes clear why the heritability studies are evidence for the heritability of IQ but not evidence that African-Americans are "genetically predisposed to be less intelligent" (to quote Ms. Grace). They can't be evidence for that since they are equally compatible with the the contrary hypothesis, namely, that "environmental factors fully explain the differences in IQ." Here is a simple example from Block that makes the point:

Consider a culture in which red-haired children are beaten over the head regularly, but all other children are treated well. This effect will increase the measured heritability of IQ because red-haired identical twins will tend to resemble one another in IQ (because they will both have low IQs) no matter what the social class of the family in which they are raised. The effect of a red-hair gene on red hair is a "direct" genetic effect because the gene affects the color via an internal biochemical process. By contrast, a gene affects a characteristic indirectly by producing a direct effect which interacts with the environment so as to affect the characteristic. In the hypothetical example, the red hair genes affect IQ indirectly. In the case of IQ, no one has any idea how to separate out direct from indirect genetic effects because no one has much of an idea how genes and environment affect IQ. For that reason, we don't know whether or to what extent the roughly 60 percent heritability of IQ found in White populations is indirect heritability as opposed to direct heritability.

Now it would be mad in this scenario to say that the lower IQ of red-haired children is a matter of a "genetic predisposition," since it is due entirely to an environmental factor, i.e., the mistreatment of a group with a phenotypic trait that is genetically based but which is otherwise unrelated to IQ. But what the evidence for the heritability of IQ across racial groups shows is compatible with both the "IQ is genetically determined" hypothesis and the "differences in IQ is environmentally determined" hypothesis. (Indeed, as Block suggests, the evidence we have about the effect of environmental variables on IQ might even slightly favor the latter, but let's bracket that since the point stands without deciding that isue.) If a purported piece of evidence does not discriminate between P and ~P, then it can't actually be evidence for one rather than the other. But Ms. Grace argues as if there were evidence for one of the propositions in question, and that she makes that inferential leap, unsupported by evidence, in favor of a vicious racist stereotype is precisely what opens her up to criticism.

I am sorry to have to spell this out in such tedious detail, since I'm sure it was obvious to many readers the first time around. But perhaps it will do some good, maybe even with the proverbial know-nothings of the blogosphere, who, alas, did not disappoint. This one, for example, despite actually making an effort, it appears, to read Ned Block's essay, announces with a sense of triumph that Block's essay does not support "Leiter's assertion that there is no genetic contribution." But, of course, I nowhere asserted any such thing: this right-wing blogger just made it up. "There is no evidence--literally none--that IQ differences between racial groups have a genetic basis" means what it says. The criticism of Ms. Grace was for drawing racist inferences without evidence and for being ignorant about the evidence and what conclusions it actually warrants. But this was, to repeat a point made by Orin Kerr, only one e-mail, for which the author apologized, and it hardly deserves this level of scrutiny considered on its own. The more interesting phenomenon now is the effort on the right to rationalize away the racist assumptions in the e-mail, and turn this into an issue of "academic freedom" or "political correctness."

UPDATE: The hapless Mr. Maguire, our random right-wing blogger of the day, updates his post and almost admits that he misrepresented what I said. But he can't quite do it, alas. He now adduces as proof that I asserted what I did not assert my first uncontroversial proposition about IQ and heredity, to wit: "There is substantial evidence that IQ is heritable (which does not mean, contrary to what many blogs, as well as the HLS student, seem to think, that it has a genetic basis)." He thinks the parenthetical is an assertion that IQ has no genetic basis, even though it refers, explicitly, to the confusion of the HLS student (and various bloggers) about heritability and genes. And what is that confusion? Thinking that the heritability of IQ is evidence that it is genetically determined. So the fact that IQ is heritable (uncontroversial fact #1 on my list) does not provide evidence ("does not mean") it has a genetic basis. That's why it is on a list with #3, "There is no evidence--literally, none--that IQ differences between racial groups have a genetic basis." How else could #1 and #3 go together? Vide Block, the post above, etc. This isn't hard. I have no doubt Mr. Maguire will surprise me, and cause me to rethink my unfair assumptions about the know-nothing blogosphere, by now retracting his mistake in toto.

[Thanks to Jonathan Falk for correcting an error in the original formulation of the point about the failure of evidence to discriminate between competing hypotheses.]

THE DUNNING-KRUGER EFFECT STRIKES AGAIN (5/4): Needless to say, Mr. Maguire, our random know-nothing du jour, did not surprise me; to the contrary, having misrepresented what I said, and thus misunderstood the argument, his only response was to repeat the misrepresentations ever more forcefully, declaring my correction of his mistake "obfsucation" and my clear statement of the argument, above, unintelligble. We may at least thank Mr. Maguire for a fine example of "condescension from below." On a more intellectually substantive note, Ned Block tells me that, time permitting, he may have some additional thoughts about these issues to share with readers of the blog in the next few days.